Curved needle chain stitch sewing machine



Plfil 24, 1934- J. v. PooLE CURVED NEEDLE CHAIN STITCH SEWING MACHINE Filed Jan. 16, 1931 2 Sheets-Sheet l jizz/572W April 24, 14934. J. v. POOLE CURVED NEEDLE CHAIN STITCH SEWING MACHINE` Filed Jan. 16. 1931 2 Sheets-Sheet 2 dZ/UZ 547%, @www @J7 #by Patented Apr. 24, 1934 UNITED STATES PfrrsN'lv oFFlcs CImvED NEEDLE CHAIN STITCH SEWING MACHINE Jesse V. Poole, Abington, Mass., assignor to Puritan Manufacturing Company,

Boston,

9 Claims.

The present invention relates to sewing machines of the type adapted to sew a chain stitch seam with a single thread, and more particularly to machines of that class which are adapted to operate on heavy materials, such as leather, boxboard and the like, in the manufacture of bags, cases, shoes, etc. Its object generally is to provide an improved machine of this nature combining the advantages of a curved needle and awl with those of cranks or eccentrics as the driving means of its working parts, whereby to secure the ability to place stitches close to overhanging parts of the work, together with extremely rapid, and at the same time smooth and quiet, operation. A more specific and particular object has been to transform a previously known type of machine, heretofore provided only with a straight needle and correspondingly moving cooperating instruments, into a curved needle machine, thereby accomplishing the union of characteristics previously mentioned.

The manner in which I have accomplished these objects and the principles and specific characteristics of the invention are explained in the following specification in connection with the description of a particular machine embodying the same. f

. In the drawings,

Fig. 1 is a side elevation of the machine referred to Fig. 2 is a perspective view of the curved awl and means for operating itwhich embody one phase of the invention;

Fig. 3 is a perspective view of the curved needle, the cast-off which cooperates with the needle in forming the stitches, and means for moving these elements in a curved path;

Fig. 4 is an end elevation as seen from the left of Fig. 1; l

Fig. 5 is a fragmentary sectional viewon line 5-5 of Fig. l;

Fig. 6 is a sectional view, broken and shortened, taken on line 6-6 of Fig. 1; l

Fig. 7 is a side elevation of the awl carrier and its operating means, with the work rest and presser foot shown in section;

Fig. 8 is a similar view of the needle and its operating parts;

Fig. 9 is a similar view of the cast-off and its operating parts.

Like reference characters designate the same 'parts wherever they occur in all the figures.

The machine comprises a base 11v adapted to be set on a bench, a column or standard 12 rising from the rear part of the base, and an arm 13 ex- (Cl. 11B-53) tending from the upper part of the column and overhanging the base. A work support structure 14 rises from the forward portion of the base and to it is secured a post 15 carrying the work supporting table 16 at its upper end. A presser foot 69Y 17 carried by a reciprocatable presser bar 18 c0 operates with the`table.

The forward end of arm 13 is provided with vertical guideways, in one of which the presser bar 18 reciprocates, and in the other of which an 65 awl operating bar 19 is confined and guided for vertical movement endwise. An extension or arm 20 projecting downward and forward from the arm 13 forms a bracket in which is mounted a stud 21, said stud providing a pivot on which is 70.A

oscillatively mounted an awl carrier in the form of a bell crank lever having arms 22 and 23. A curved awl 24 is secured against one side of the carrier arm 22 by a clamp 25 which is screwed detachably to the side of this arm. The other arm 23 of the awl carrier is connected by a pivot 26, link 27, and pivot 28 with a block 29, said block being made with a passage which ts the bar 19 so that the block may be applied removably to the bar. A set screw 30 is threaded into Va tapped 80 hole in the block which intersects said passage and secures the block to the bar.

The awl is curved on the arc of a circle concentric with the pivot stud 21 and is movable in a path which forms a continuation of the same arc so as to penetrate and withdraw from work placed on the work table 16. The awl carrier is placed with its arm 22 approximately vertical and its arm 23 approximately horizontal, and in such position that when the bar 19'is brought to its 90 lowest limit of motion the awl is retracted clear of the work, and when the bar is raised the awl is moved downward across the plane of the work table and into the slot 31 therein.

A feed arm 32 is mounted on a horizontal shaft 95 the same vertical plane with the bar 19. They are confined slidingly in guideways in the feed arm 32 and are adapted to be reciprocated endwise therein.

Thev feed arm 32 is formed with an extension 37 rising from its upper end to a termination beside the lower end of bracket 20, and it is perforated transversely to receive a pivot pin 38 on which are mounted a needle carrier in the form of a bell crank lever having arms 39 and 40, and a castoff carrier in the form of a substantially straight lever having a rear arm 4'1 and a forward arm with a lateral oifset 42. The arrangement of these last named parts is such that the pivot 38 is substantially in alinement with the pivot 21 of the awl carrier.

A curved needle 43, the curvature of which is concentric ywith pivot v38 and `has thesame radius as the curvature of awl 24, is clamped to one side of the carrier arm 39 by a clamp 44 which is secured to said arm. Arm 40 of this carrier extends rearwardly and is coupled to the reciprocative bar by a block 45 and a link 46, said block being apertured to fit the bar and being secured thereon by a set screw, while the link 46 is connected .to the block and the carrier arm by pivots 47 and 48, respectively.

The cast-0E consists of two ,fingers 49 and 50 which are located at respectively opposite sides of the needle, closely embrace the needle, and .are curved with the same radius of curvature. They are mounted on shanks 51 and 52, respectively, which project from the end of the carrier offset 42 and are suitably designed to locate the cast-off lingers in the relationship above described. Preferably these cast-off fingers and their Shanks are each made of a single piece of vstiff steel wire, or thin bar stock, set tightly into holes provided for their reception in the cast-off carrier, and bent at their other ends to the appropriate configuration. Arm 41 ofthe cast-off carrier is -connected to the reciprocating bar 36 by a block 53 vand link 54 substantially like the corresponding block and link of the needle carrier. A detail o-f i the connection between .the carrier arm and link,

which is shown with `the awland cast-off carriers in Figs. 7 and 9, consists in slotting the arm which receives the connecting pivot, by means of a slot 55 which opens from one side of the arm into the pivot receiving hole, and providing a take up screw 56 for `drawing the parts at opposite sides of the slot together so as to clamp the pivot. This same ydevice may be applied to the arm 4G of the needle carrier, and to either or both pivot sockets .of any or all of the connecting links 27, 46, 54.

.eccentric rod 62 ,passes downward through the `column 12 and is coupled to an arm l63 on a rock .shaft 64, having bearings in the base, to which rock shaft a second arm Y65 is secured. Arm '65 is coupled to bar 35 by a link '66.

From the eccentric 61 an eccentric rod 67 passes to an arm 68 on a rock shaft 69, mounted in the base parallel to shaft 64, which carries also an arm '70 coupled to bar 36 .by a link 71.

, The eccentrics 60 and 61 are timed with respect .to .the crank 58 so as to cause the needle to follow the fawl as vthe latter withdraws after puncturing the work, receive the thread, and withdraw through the work, pulling after ita loop of the thread; and to move the cast-off fingers with, and a-lso independently of, the needle so as to remove vthe thread loop v'from the needle hook and hold it open to .receive another loop of `thread drawn through the work by the needle in forming the next stitch.

'The thread -is so laid in the needle hook by a `looper 72 carried by a looper arm 73 which is operated by an eccentric 74 on the driving shaft in a manner well known in this art.

The feed arm 32 is oscillated to move the needle sidewise for feeding the work, and return the needle to previous position after each feeding step, by means of a cam 75 on the driving shaft which is embraced by the arm 76 of a forked 'lever 77. A second lever 78 is secured to the rock shaft 33 on which the feed arm is secured, by means of an intermediate distance varying mechanism which enables an invariable throw of the lever 77 to be converted into a longer or shorter feeding step of the feed arm. Such distance changing mechanism is an old feature in this art, illustrative embodiments of which are shown in patents No. 490,854, January 31, 1893, of F. W. Merrick, and No. 711,909, October 21, 1902, of H. C. Peters and forms no part of the present invention. Therefore in the interest of simplicity and brevity I have refrained from showing it herein.

I have chosen for the working out of my new invention a Vcommercial sewing machine which has long been known and used, and which Iv have reorganized. In the machine here illustrated the M motions of the presser foot, feed arm, reciprocat- 1D0 ing bars 19, 35 and 36, the looper arm 73, and the `mechanisms `for giving such motions and operating such parts, are the saine as in the commercial machine. The reorganization which I have effected, and one phase of the invention, comprises the substitution of curved awl, needle and lcast-off fingers for the straight implements used in the prior commercial machine, the provision of new carriers for these implements and supports for such carriers separate from the bars 112i previously used as carriers for the implements of lthe old machine, and motion transmission 4connections from such bars to the new carriers, vall of which have been described in detail in the foregoing specification. A further and broader phase of the invention comprises the generic combination accomplished by such reorganization, its principles, and equivalent embodiments 'of such principles i-n other forms. Y

What I claim and ldesire to secure -by Letters '1:29 Paten-t is:

1. A chain stitch sewing machine having 4curved awl, needle and cast-off movable in substantially coaxial curved paths, an osc'illative vfeed arm supporting the needle and cast-off, pivoted to i125 -sw-ing about an axis at a distance from, and transverse lto the axis of said paths, and 4ext-ending from its pivot toward the latter axis, and means for operating said Ielements in their prescribed order for feeding the work and sewing a chain stitch seam.

2. A chain stitch sewing -machine comprising a plurality of bars, each mounted for endwise reciprocation, a curved oscillative awl connected for angular movementlby reciprocation of 4one of Vsaid bars, a curved oscillative needle connected for angular movement by recipro-cati'on of another of said bars, a drive shaft, driving cranks on said shaft, and connecting mechanisms from the resective cranks to said bars for reciprocating 146 ein.

3. In `a .chain stitch sewing machine having a stationary frame, a bar reciprocatably mountedin said frame, an oscillative feed arm, a bar carried by said feed arm and movable thereinreciprocat- 145 .ably lengthwise, `the last named .bar being imovable fby .the feed arm laterally into .and out 'of vapproximate falinement with ithe first bar, pivo'ted ies 'carriers mounted respectively .on the :frame and uon the feed arm, and each coupled with Aone of 150 said bars for oscillation by the reciprocation thereof, a curved needle secured to one of said carriers with its axis of curvature substantially coinciding with the oscillative axis of the carrier, and a curved awl secured to the other carrier and similarly arranged with respect to its axis of oscillation.

4. A machine as set forth in claim 3 in which the axes of the carriers are in substantial alinement in the direction of movement given by said feed arm to the carrier thereon.

5. A sewing machine comprising a work piercing awl, a needle, a cast-off cooperating with said needle in forming a chain stitch seam, pivoted oscillative carriers for said awl, needle and castoif arranged on approximately the same axis, the awl, needle and cast-olf being curved concentrically with said axis and all located at approximately the same distance therefrom, reciprocating bars coupled to the several carriers, a drive shaft having cranks, separate driving connections from the several cranks to each 0f said reciprocating bars respectively, an oscillative feed arm to which two of said carriers are pivoted and in which the reciprocating driving bars thereof are mounted, and means for oscillating said feed arm in the direction of said axis.

6. In a chain stitch sewing machine, an oscillative feed arm, bars carried reciprocatively by said feed arrn and extending substantially parallel to a line radial to the axis of reciprocation of the arm, said arm having an extension at one side of the outermost ends of the bars, two carriers pivoted to said extension on a common axis and each coupled with one of said bars to be oscillated by reciprocation thereof, a needle secured to one of said carriers and curved about the axis thereof, and a cast-off secured to the other of said carriers having a finger located close beside the needle and movable lengthwise thereof.

7. In a machine as set forth in claim 6, the

said cast-off comprising two Shanks projecting from the carrier toward the needle and cast-off fingers on the ends of the respective Shanks, said fingers lying on opposite sides of the needle in close proximity thereto and extending and being movable lengthwise of the needle.

8. In a sewing machine of the character described, a supporting element, a carrier pivoted to said supporting element and having an operating arm, a reciprocative bar protruding at one end clear of adjacent parts of the machine, a block detachably secured to the protruding end of said bar, and a link pivoted at opposite ends to said block and said arm, respectively.

9. A sewing machine comprising a base, an upright, and an overhanging arm at the top of the upright, an endwise reciprocative bar mounted in said overhanging arm and extending toward the base, an oscillative feed arm rising from the base toward said bar, a reciprocative bar mounted in said arm projecting from the upper end thereof, a bracket extending downwardly and forwardly from the overhanging arm, a projection extending upwardly and forwardly from the feed arm and overlapping at its upper end the lower end of said bracket, carriers mounted respectively on said bracket and on said projection with their axes in substantial alinement, each having a rearwardly extending arm and the carrier on the bracket having also an upwardly extending arm while that on the feed arm projection has a downwardly extending arm, connecting links coupling each of the rearwardly extending carrier arms separately with one of said reciprocating bars, an awl secured to the other arm of one of the carriers, and a needle secured to the other arm of the other carrier, said awl and needle being curved concentrically about said axes and at the same distance therefrom.

JESSE V. POOLE. 

